Candidate: My long-term career goal is to become a well qualified, extramurally funded independent researcher that will have an impact in reducing occupational exposure to respiratory hazards. My background is in studies of human aerosol inhalability and personal aerosol sampler performance. I have a PhD in Industrial Health and an MPH in Industrial Hygiene & Hazardous Substances, both from the University of Michigan. I also have 4 first-author peer-reviewed publications and significant experience presenting at international and national conferences and meetings. I am currently a tenure-track Assistant Professor at the University of Utah, Rocky Mountain Center for Occupational & Environmental Health (RMCOEH). Through this proposed K01, I will build on my dissertation and previous experience to transfer it into the development of innovative projects that advance the science of workplace air sampling to better protect worker's health. Career Development Plan: This K01 award will further my goal to be an independent academic researcher by providing an intensive, supervised career development experience in occupational health research leading to research independence. My ultimate career goals are: 1. Develop innovative R01 research proposals 2. Establish a high-quality, extramurally funded research program 3. Provide superior graduate level teaching My Mentor Advisory Committee (see Research Strategy for specific expertise) consists of: 7 Rodney Larson, PhD, CIH (primary mentor; Industrial Hygiene); 7 JoAnn Lighty, PhD (Chemical Engineering); 7 Samuel Paik, PhD, CIH (Industrial Hygiene - Lawrence Livermore National Laboratory); 7 Eric Pardyjak, PhD (Mechanical Engineering); 7 John Veranth, PhD (Pharmacology & Toxicology); and 7 Eric Wood, MD, MPH (Occupational Medicine). My career development plan includes: 1) monthly meetings with my committee, 2) obtaining a Research Investigator Certificate, 3) participating in Journal Clubs, 4) participating in standards setting, 5) technical coursework in Fluid Dynamics, and 6) significant experiential learning. The RMCOEH is a NIOSH-sponsored Education & Research Center (ERC) with well-qualified faculty and significant ties to other academic departments and institutions, relevant industries and government entities. Together with my focused career development plan, this fosters an institutional environment committed to my development into a productive, independent investigator. Research: The goal of this research is to design, develop and test a new personal aerosol sampler that will collect a more biologically-relevant fraction of airborne particulates. This would allow improved quantification of and protection from worker's health risks. A unique aspect of this project will be sampler testing in a specially-designed low speed wind tunnel that simulates indoor exposure scenarios. This environment is more relevant to typical worker exposures than other sampler testing methods and has not been used for sampler development. The research plan is based on the improvement and/or modification of existing personal inhalable aerosol samplers. Most particle size-selective aerosol samplers that are currently used to measure personal exposures in the workplace (i.e., inhalable, thoracic or respirable samplers) are based on criteria established for particle penetration into various portions of the human respiratory tract. In reality, some particles that are inhaled during breathing will be exhaled without deposition into the body. The true biologically-relevant dose would therefore not include the exhaled aerosols. A promising method for a deposition sampler involves porous polyurethane foam inserts that act as collection media for particle size selectivity. In the proposed research, this type of foam will be used in series with a commercially-available inhalable aerosol sampler (n=324 samples). In this way, the aspiration efficiency of the sampler (i.e., what size particles it will collect) can be modified by altering the porosity and thickness of the foam. Using t-tests and bias maps, the performance of these sampler prototypes will then be compared to newly-proposed criteria for deposition sampling. Ultimately, this research aims to improve existing sampling techniques in order to provide more biologically-relevant exposure assessment data, which would strengthen the relationship between exposure and disease in epidemiological studies, while also better protecting worker's health.